A shudder when going along x-axis with grain


I have just re-tensioned my y belts and now when I cut with 3.175 end mill along the x-axis with the grain, there is a shudder from the router in about the middle half of the board.

I assembled my new machine last week and did a few test carves with no problems.
Today, I re-tensioned the y-axis belts and recalibrated the x and y axis due to some belt stretch.
Now the shudder. I can just light hold the router mount as it goes along the x-axis and it will stop with a small amount of effort.

Any ideas would be greatly appreciated.


First thing would be to verify your feed rate. If your running the dewalt on setting 1 then you have 16000 rpm. Find out the chip load for your particular bit and calculate the feed rate you need. To fast or too slow can cause chatter, rubbing. You will pre maturely burn up and dull your bit. Not to mention the noise lol.

Check the V wheels for correct adjustment as well.
As Curtis said feed rate can cause chatter as well.

I have noticed that my cuts are not vertically square when cutting along the x-axis. How do I square the router vertical along the y-axis. It is the vertical that is not square. The instructions mention the squaring on the x but not y

Tramming a CNC: